CrashPlan users are sometimes confused by the fact that the backup rate they see from the CrashPlan app is significantly different from the bandwidth they receive from their Internet Service Provider (ISP). The purpose of this article is to explain how the CrashPlan app's effective transfer rate differs from the bandwidth provided by your ISP, as well as some of the factors outside of Code42's control that can affect backup rates.
Before you begin
You may be able to make some adjustments to the CrashPlan app to speed up your backup.
- CrashPlan subscribers share bandwidth when backing up to the cloud. As a result, upload speeds may not match maximum speeds of an individual’s Internet provider.
- Code42 monitors usage across our data centers and strategically adds capacity (servers, storage and bandwidth) to our infrastructure to deliver the best upload speeds we can.
Why backup speed and bandwidth differ
Bandwidth is a measure of theoretical network capacity, but in reality, the actual achieved throughput that any device or application gets will usually differ from this theoretical maximum. The protocols that your devices use to communicate over the Internet take up overhead, bandwidth is shared with other applications, and network latency can slow down connections.
Another factor that causes the backup speed to differ from the network bandwidth and throughput is the fact that the CrashPlan app compresses the data before sending it (unless this default settings is changed). This usually results in the effective transfer rate being higher than the actual transfer rate. An example will help to make this clear: CrashPlan app user Susan has 10 GB of data on her system to be backed up. After the CrashPlan app compresses and encrypts the data, it now takes up only 8 GB of space. Her CrashPlan app transfers that 8 GB of data at an actual transfer rate of 1 Mbps. However, the effective transfer rate is actually 1.25 Mbps, or 25 percent higher, due to the data compression.
The main concept to keep in mind is that the backup speed is not the same thing as bandwidth or throughput:
- Bandwidth is a theoretical maximum, and applies only to your connection to your ISP, not the Internet in general
- Actual throughput or file transfer speed is the performance that your device sees in actual operation
Backup speed and effective transfer rate depend on both of the above, and also on data compression and other factors, as described below
Upload versus download speeds
ISPs often provide different amounts of bandwidth for downloads and uploads. The download speed is typically greater than the upload speed. Regardless, it is a good idea to find out from your ISP what level of service you are supposed to be getting, and to then test your service with one of the many ISP speed tests that are freely available on the Internet. Knowing the speed you have been promised by your ISP, and what you are actually receiving, will allow you to verify that you are getting the service you are paying for, and that your backup speeds are not being slowed down by your ISP.
Other facts to keep in mind:
- Backups are an upload operation, because the data is going from your device to the Code42 cloud
- Restores are a download operation, because the data is going from the Code42 cloud to your device
External factors affecting backup speed
Various factors outside of Code42's control affect your backup speed. The effective transfer rate between your device and our data centers depends on the bandwidth provided by your ISP, as well as network speeds on nodes between your ISP and our data centers. Even if a speed test of your ISP shows that your currently available bandwidth is high, network congestion elsewhere can cause backup speeds to slow down. The effective network speed between the CrashPlan app and Code42's servers affect the backup speed.
What you can do
- Make sure that you haven't used CrashPlan's network throttling feature to limit the transfer rate of the CrashPlan app.
- Please make sure that your device is operating optimally, meets our system requirements, and that it has enough RAM and disk space available.
- Networking equipment such as routers, wifi access points, and firewalls should be functioning optimally. Ensure that your equipment meets system requirements, and try rebooting your router or cable/DSL modem.